91 Dually Rear Diff Health??

[lazermule]

I rolled under the dually that I just bought and checked the rear diff gear oil. Was about 1 inch low and had small metal shavings in it.

Should I just change it a few time in hopes to clean it up? Or should pull the axles and bearings and flush the tubes and clean all out of the bearings?

No big metal pieces just small metal flake like found in metalic paint.

So what is the diagnosis? Is the rear diff on its way out???

Thanks,

LM

 

[tonkadoctor]

If the wheel seals and pinion seal aren't leaking and the rear isn't making unusual noises it's probably normal wear and too long between fluid changes.

Leaking pinion and axle seals are often an early indication of a bearing going bad but can also be attributed to dried seals from sitting, age, dirt etc....

 

[lazermule]

The pinion seal is leaking ever so slightly. I couldn't detect any endplay or lateral movement on the pinion either. I have never been into that area of a Dana 70, so I'm not sure what is involved. I'll probably just change the fluid a few times here in a few thousand miles and see if it cleans up.

I guess if this rear goes out, I have a replacement out of my 84 F350 dually, but I believe that one is only a Dana 60 and has a 4:10 ratio where this one is in the 3:50 range so I'd rather keep this one healthy.

Thanks,

LM

 

[Cowboy_Customs]

The chevy dually rear is a 70 as is the dodge dually rears. They are completly interchangable.
The metal you see sounds normal, just been awhile sence the last change.